Friday, August 29, 2008

College Station, TX. Yesterday the entomology department at Texas A&M University suffered a shocking loss with the unexpected death of Professor and Extension Entomologist, Dr. John Jackman.

John was a wonderful colleague with an encyclopedic knowledge of insects. For all the tough entomology questions (and there are lots of them) he was the go-to guy for me and my colleagues . Whenever there was a question I couldn't answer, I'd call John.

For the past 19 years since I've been here, John has been the department's principal responder to phone calls received from the public--no easy task. In addition, he was one of the first extension faculty to see and take advantage of the Internet's potential for public education. He built the departmental home page, the second most visited website in the Texas AgriLife Extension system. I've often wished I had half the computer knowledge he had.

John loved the outdoors, and taught courses on aquatic entomology and, most recently, fly tying. The fly tying course was an innovative class that integrated concepts of aquatic biology with art and craftsmanship. It was offered through Texas A&M's entomology and art programs.

He was a long-time volunteer in the Boy Scouts of America, a dedicated husband and father to three sons. He leaves a hole that will never be filled.

Since 2003, I've been privileged to work with John and Extension colleague, Carlos Bogran, on the Texas Master Gardener Entomology Specialist program, an intensive, one-week course on entomology for Master Gardeners and Master Naturalist volunteers. To see images of John at work with the program, click here. Without John's leadership and initiative it never would have happened. John, we'll miss you greatly.

AgriLife Extension's AgNews this weekend posted a brief obituary of John with a link to the College Station Eagle's guest register where memorial notes can be posted online.

Monday, August 25, 2008

Dallas, TX. If you've been getting higher numbers of calls than normal about swarming insects in customers' homes recently, the culprit may be rover ants.

Last month I posted an entry about two new ant pests for Texas, in which I discussed the true identity of a tiny rover ant that has been growing in importance throughout Texas. Since that post, the identity of the rover ant has been confirmed as the dark rover ant, Brachymyrmex patagonicus. This ant is believed to be a relatively new immigrant from South America, and is one of the latest in a string of exotic pests that seem to have found themselves a new home in the U.S.

The swarmers are similar in size to a Pharoah ant swarmer, about 3/16 inch (4 mm) long and brown in color. Like the workers, they have a 9-segmented antenna and single node (pedicel) between the thorax and gaster. This is the first year I have had so many ant swarmers submitted in mid-summer, and the most likely explanation seems to be the spread of this new ant.

Rover ant swarmers seem to emerge at night and hover weakly around lighted rooms. As with other ant swarmers, there is little that can be done to prevent the swarms, short of finding and sealing the small holes or cracks from which they emerge (an unlikely task). Fortunately, swarmer emergence is relatively short-lived, usually a few days to a week, and are at worst a minor nuisance. The worker ants can be more troublesome because of their persistence in returning to a variety of indoor sites.

Rover ants have been difficult for the industry to control. Janis Reed, of ABC Pest and Termite in Austin, presented her observations of the best control methods for this ant at the recent National Conference of Urban Entomology meetings in Tulsa, OK. She considers rover ants very difficult to control, and a pest for which there is yet no magic bullet.

Technicians at ABC Pest and Termite rely on a combination of baits and sprays. Standard ant sprays reportedly provide little, or inconsistent, control of these ants; however Reed reports that combination sprays, containing both a pyrethroid and a neonicotinoid insecticide (such as the new Transport Insecticide, containing both bifenthrin and acetamiprid), seem to provide improved control. Gel and liquid baits may provide temporary suppression, but continued inspections and baiting are needed to keep ants from returning.

Rover ants are honeydew feeders, often milking scale insects, aphids and other sap-feeding insects for their sweet secretions. Rover ants are even reported to feed off the secretions of subterranean aphids feeding on plant A good IPM approach, therefore, would be to treat nearby trees to eliminate sap feeding insects, in addition to using baits and barrier sprays on the outside of the building. This approach has a better chance of providing long-term ant suppression than either of these tactics used alone.

Monday, August 18, 2008

Dallas, TX. It's no secret that bed bugs are one of the biggest new challenges that the pest control industry has faced in many years. In some ways, as a pest control professional, bed bugs are your worst nightmare. Infested structures are mostly hotels and apartments, arguably two of the least profitable and most difficult kinds of accounts to service. Infestations are usually centered around beds and bedrooms, often the most cluttered and private rooms of a home. Good service is extremely time consuming and requires diligent follow-up to be successful.

On the other hand, bed bugs open up an opportunity for astute and detail-oriented companies. A company that can master bed bug control can easily open a growing niche in the pest control business. And there's no sign of bed bug problems slowing down or going away.

I'm not an expert on bed bug control. I'll leave that title to you guys who have a dozen or more jobs under your belt, and who have achieved a high level of customer satisfaction. But I'd like to share a few facts about bed bug control gleaned from the researchers:

Bed bug control is time consuming. In 2005, a survey of 225 pest control companies offering bed bug control services was conducted by Cornell University's Survey Research Institute (American Entomologist, Summer 2006). Most companies spent 30-60 minutes inspecting and preparing a typical bedroom and at least one hour to treat. This is not a fly-in, fly-out kind of job.

Count on multiple visits to get satisfactory control. In the Cornell study 62% of the companies claimed to control bed bugs in 2-3 visits. In a study conducted by Bayer Environmental Science, and reported by Byron Reid at last May's National Conference of Urban Entomology, U.S. pest control companies required 2.9 visits on average to control bed bugs.

Lest you think lots of pesticide is required for bed bug control, the Bayer PMPs averaged only 3/4 gallon of liquid spray mix per apartment during the first visit, and approximately 1/4 gallon thereafter. The volume of sprays used should be relatively low, but the number of cracks and crevices treated is time consuming.

In the Bayer (manufacturer of Suspend) study, the number of callbacks were reduced from 3.45 to 1.75 when the PBO-containing product, Kicker®, was added to Suspend® sprays. Current data does suggest that pyrethroid insecticides might benefit from the addition of a synergist , like PBO. This is likely due to a relatively high incidence of resistance being found among bed bug populations in the U.S., as reported by Romero et al. in the Journal of Medical Entomology this spring (March 2007 , pp. 175-178).

To see more images of bed bugs and a bed bug treatment, visit my Flickr site here. Thanks to Carlos and Manuel Campos of C&M Pest Control in Dallas, for allowing me to tag along on a recent bed bug job.

Tuesday, August 12, 2008

I was reading a new product label this morning and came across a phrase that caught my attention. The label stated that "It is impossible to eliminate all risks inherentlyassociated with the use of this product."

This phrase, undoubtedly drafted by a lawyer and--I suspect--ignored by most users of the product, reminded me of a profound principles of pesticide toxicology and safety testing--one that I think few of us fully understand or appreciate: "It's impossible to prove that a pesticide is absolutely safe."

Science is a wonderful process. It allows us to discover useful things about our world. It forms the basis for new technology, answers our deepest questions about the universe, and brings wonder into our lives. Science, however, has it's limits. One of its limits is that it cannot prove absence of harm with complete certainty. It's the old "you can't prove a negative" argument.

Let me give an example. If my job is to test the safety of a new pesticide, I may expose a variety of organisms to my product to see if anything bad happens. Toxicologists routinely do this in laboratories with mice and rats and bacteria. Some tests are designed to measure acute toxicity, others look for evidence of mutations, others for cancer or other chronic disease. Suppose in the course of my testing all the rats develop cancer. This would be alarming evidence that my pesticide might be a human carcinogen. Evidence is strengthened if there are epidemiological studies that show a pattern of elevated cancer rates in humans exposed to the pesticide during its manufacture or use.

Now suppose there are no signs of cancer or other illness in my animals. Have I proved that my pesticide is safe? No. Science, because of physical and economic limitations, cannot prove safety with absolute certainty. For example, pesticide toxicology studies are not generally performed on people for ethical reasons. And people, despite our many occasional similarities, are not rats. Also, we cannot rule out all possible genetic, environmental or health factors that might influence carcinogenicity.

We know of cases, for example, where pesticides have proved exceptionally toxic to people taking certain prescription drugs. In these cases the drugs interfered with the user's ability to detoxify the pesticides, making them more toxic.

If we insisted that science provide absolute proof of safety, the science would become almost infinitely expensive. The best we can do is require a robust set of testing requirements, and base our decisions on the best available science. In addition, there should be a system of reporting suspicious patterns of health complaints associated with pesticide manufacture and use.

This is exactly what we do in the United States. The U.S. has, arguably, one of the best pesticide registration and approval processes in the world. New pesticides are incredibly expensive to register, in large part because of the safety testing required by the U.S. Environmental Protection Agency. The biggest beneficiaries of this regulatory process are those of us who work with pesticides on a daily basis.

So what's a pesticide applicator to do? Follow the label. The answer is so obvious that we often forget to do it. Labels are written to provide wise protection from the admitted limitations of our science when it comes to safety testing. From the precautionary statements, to the requirements for protective clothing, pesticide labels provide uncertainty protection.

Though they can be extremely uncomfortable in heat (especially in our part of the country), gloves, respirators and chemical resistant clothing, when required on the label, are essential to our safety. It may be necessary to explain this to a customer who balks at an applicator wearing gloves or breathing filters. They can be told that the extra protection is required by law (the label is the law) because, unlike them, applicators are exposed on a daily basis to our pesticide tools. It's not an admission of toxicity; it's a common sense precaution. It's an acknowledgement that we don't take unecessary chances with ours or our customer's health.

We should remember that there will always be risks working with pesticides, as with nearly any other consumer chemical product. That's the surprisingly wise message of the pesticide label.

Wednesday, August 6, 2008

Dallas, TX. We hear of rare illnesses and diseases nearly every day in the newspaper or on television. After a while, I think most of us become a little jaded, and tend to forget or ignore threats that have not affected us personally. One of these relatively obscure diseases is a mosquito-borne illness called West Nile virus. Since 2002 Dallas county has averaged 45 clinical cases and two deaths a year.

These numbers may not seem like much...on paper. But these are real people who contract mosquito-borne disease every year. They include our neighbors. Friends. Parents. Teachers. The tiny bite of a Culex mosquito can, if infrequently, lead to a life-changing illness. Many of us reading this post may have already been infected by this virus. Only 20% of infected persons show any signs of the disease, and most of those will have little more than the sniffles. One in 150 infected persons, however, will contract the more serious central nervous system form of the disease.

Despite my awareness of West Nile virus and the clinical implications of the disease, until I met actual victims I don't think I really appreciated the power of this virus to potentially affect my life or the lives of loved ones.

Dr. Don Read and his wife Roberta lead a support group for victims of West Nile virus in the Dallas area. There are only a handful of such groups in the country, but they can be a godsend for people who have suffered from one of the more serious cases of infection. Last week I had the chance to attend one of their support group meetings at Medical City Dallas Hospital. It was a sobering experience to listen as people shared their encounters with the disease.

This month's meeting was covered by Reporter Melissa Maynarich from Oklahoma City's CBS Channel 9 News. She and her photographer posted a video story of some of the folks at this meeting. If you are interested in the human side of the West Nile virus story, check it out at http://www.news9.com/Global/story.asp?s=8764354

It might make you look at mosquitoes a little differently. I know I'm reaching for the repellent more these days. If you know of someone who has suffered from West Nile virus, or just to learn more about the disease and the support group in Dallas, check out the Dallas County Health Department's website on West Nile virus.

Tuesday, August 5, 2008

It seems Hurricane Dolly brought with her more than rain. Following the record rains and flooding mosquitoes have also arrived by the semi-truck load.

Mosquito pressure is often measures in terms of numbers of landing rate per minute. A volunteer will expose a leg and another person will count the number of mosquitoes that alight on the exposed skin for one minute. A recent Harlingen survey put the average per minute landing rate at 120, with a high in one location of 384 mosquitoes per minute! That's a lot of mosquitoes.

A regional spraying effort started this week in south Texas. Airplanes will be applying the insecticide Dibrom to most parts of the lower Rio Grande valley to suppress numbers of especially floodwater mosquitoes that are the first species to come out after a flooding event. For more information about the spray program, see the August 2 article in the Rio Grande Guardian.

The ironic thing about these efforts is that floodwater mosquitoes pose a relatively low threat for arthropod-carried viruses, such as encephalitis and West Nile virus. The mosquitoes that carry these disease pathogens typically come out once waters begin to subside and leave numerous pools of stagnant, standing water. Not to say that spray efforts will not be without effect. Population numbers of the levels described for Harlingen would leave anyone miserable and crying for relief.

Once the huge numbers subside, and the spray planes return to their bases, the pest control industry will have an important role to play in helping reduce the risk of bites and disease. Experienced PMPs can point out to people areas where disease-carrying mosquitoes breed in their own backyards. In addition, the use of residual insecticides applied carefully to mosquito resting places in backyards and surrounding trees can significantly lower mosquito biting rates.

In one study conducted in Kentucky, and reported in the May, 2005 and October, 2006 issues of PCT magazine, backpack mistblower sprayers provided up to 6 weeks suppression of mosquitoes in backyards. Such treatments provide a valuable service to residential customers and can even reduce the risk of mosquito-borne disease by reducing populations of Culex mosquitoes, the primary vector of WNV and the various encephalitis diseases.

With today's landing of tropical storm Edouard, mosquito control will be an important issue for the pest control industry in Texas for the next two months. If you own a business in one of the areas affected by storms this summer, you owe it to yourself and your customers to read the research updates in PCT magazine, linked above.

Monday, August 4, 2008

Scorpions pose one of the most difficult control challenges for PMPs in Texas and other parts of the southwest. Part of the problem stems from the difficulty in monitoring scorpions. One of the more effective tools for spotting and collecting scorpions is the UV blacklight.

Scorpions are one of the few nocturnal arthropods that fluoresce, or glow, brightly under UV light. This greatly facilitates locating and removing active scorpions, although the work does have to be done at night.

I often get requests from PMPs for a good source of blacklights. Bioquip Products is currently offering 10% off an inexpensive, hand-held blacklight unit that should be useful for spotting scorpions at night. If you have an account with a chronic scorpion infestation, and would like to see what's going on at night, check them out at http://www.bioquip.com/specials/product_special.asp

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About Me

I have served as entomology specialist for Texas AgriLife Extension since 1989. I get to work with, and for, a bunch of great people including pest management professionals, school facilities managers, extension volunteers, researchers and other extension professionals. My areas of specialty center on research on insects affecting man including spiders, scorpions, fire ants, termites and others. My program also focuses on training school maintenance professionals in principles of integrated pest management (IPM). Our goal is to make schools healthier, cleaner places to study and live.